]> rtime.felk.cvut.cz Git - sojka/can-utils.git/commitdiff
Complete rework of CAN netlink gateway.
authorOliver Hartkopp <socketcan@hartkopp.net>
Sat, 10 Apr 2010 16:38:48 +0000 (16:38 +0000)
committerOliver Hartkopp <socketcan@hartkopp.net>
Sat, 10 Apr 2010 16:38:48 +0000 (16:38 +0000)
Major changes:

- rework internal structures to prepare routings and modifications of CAN traffic also to non-CAN interfaces
- fix reading of netlink messages in cangw.c (added RTCAN_RTA / RTCAN_PAYLOAD macros)
- rework reading of gw-job lists in cgw_dump_jobs()
- rename of functions and API definitions to have a common namespace cgw_
- added infrastructure to perform crc8 and xor checksums in CAN frame data[]

TODO:

- add and test functionality for crc8 and xor checksums in CAN frame data[]
- add help text for crc8 and xor checksums in CAN frame data[]

cangw.c

diff --git a/cangw.c b/cangw.c
index dd81003f0bae3b6df6532928d451b5204916dde7..d8757e3c01bcf07b3838ca9fe9cbeeab2981224d 100644 (file)
--- a/cangw.c
+++ b/cangw.c
@@ -72,6 +72,9 @@ struct modattr {
 } __attribute__((packed));
 
 
+#define RTCAN_RTA(r)  ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct rtcanmsg))))
+#define RTCAN_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct rtcanmsg))
+
 /* some netlink helpers stolen from iproute2 package */
 #define NLMSG_TAIL(nmsg) \
         ((struct rtattr *)(((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
@@ -128,6 +131,26 @@ void printmod(const char *type, const void *data)
        printf(" ");
 }
 
+void print_cs_xor(struct cgw_csum_xor *cs_xor)
+{
+       printf("-x %d:%d:%d:%02X ",
+              cs_xor->from_idx, cs_xor->to_idx,
+              cs_xor->result_idx, cs_xor->prefix_value);
+}
+
+void print_cs_crc8(struct cgw_csum_crc8 *cs_crc8)
+{
+       int i;
+
+       printf("-c %d:%d:%d:",
+              cs_crc8->from_idx, cs_crc8->to_idx,
+              cs_crc8->result_idx);
+
+       for (i = 0; i < 256; i++)
+               printf("%02X", cs_crc8->crctab[i]);
+
+       printf(" ");
+}
 
 void print_usage(char *prg)
 {
@@ -160,11 +183,20 @@ void print_usage(char *prg)
        fprintf(stderr, "\n");
 }
 
-int parse_mod(char *optarg, struct modattr *modmsg)
+int b64hex(char *asc, unsigned char *bin, int len)
 {
-       char *ptr, *nptr;
        int i;
 
+       for (i = 0; i < len; i++) {
+               if (!sscanf(asc+(i*2), "%2hhx", bin+i))
+                       return 1;       
+       }
+       return 0;
+}
+
+int parse_mod(char *optarg, struct modattr *modmsg)
+{
+       char *ptr, *nptr;
        char hexdata[17] = {0};
 
        ptr = optarg;
@@ -223,14 +255,172 @@ int parse_mod(char *optarg, struct modattr *modmsg)
        if (strlen(hexdata) != 16)
                return 6;
 
-       for (i = 0; i < 8; i++) {
-               if (!sscanf(&hexdata[i*2], "%2hhx", &modmsg->cf.data[i]))
-                       return 7;       
-       }
+       if (b64hex(hexdata, &modmsg->cf.data[0], 8))
+               return 7;
 
        return 0; /* ok */
 }
 
+int parse_rtlist(char *prgname, unsigned char *rxbuf, int len)
+{
+       char ifname[IF_NAMESIZE]; /* internface name for if_indextoname() */
+       struct rtcanmsg *rtc;
+       struct rtattr *rta;
+       struct nlmsghdr *nlh;
+       unsigned int src_ifindex = 0;
+       unsigned int dst_ifindex = 0;
+       __u32 handled, dropped;
+       int rtlen;
+
+
+       nlh = (struct nlmsghdr *)rxbuf;
+
+       while (1) {
+               if (!NLMSG_OK(nlh, len))
+                       return 0;
+
+               if (nlh->nlmsg_type == NLMSG_ERROR) {
+                       printf("NLMSG_ERROR\n");
+                       return 1;
+               }
+
+               if (nlh->nlmsg_type == NLMSG_DONE) {
+                       //printf("NLMSG_DONE\n");
+                       return 1;
+               }
+
+               rtc = (struct rtcanmsg *)NLMSG_DATA(nlh);
+               if (rtc->can_family != AF_CAN) {
+                       printf("received msg from unknown family %d\n", rtc->can_family);
+                       return -EINVAL;
+               }
+
+               if (rtc->gwtype != CGW_TYPE_CAN_CAN) {
+                       printf("received msg with unknown gwtype %d\n", rtc->gwtype);
+                       return -EINVAL;
+               }
+
+               /*
+                * print list in a representation that
+                * can be used directly for start scripts.
+                *
+                * To order the mandatory and optional parameters in the
+                * output string, the NLMSG is parsed twice.
+                */
+
+               handled = 0;
+               dropped = 0;
+               src_ifindex = 0;
+               dst_ifindex = 0;
+
+               printf("%s -A ", basename(prgname));
+
+               /* first parse for mandatory options */
+               rta = (struct rtattr *) RTCAN_RTA(rtc);
+               rtlen = RTCAN_PAYLOAD(nlh);
+               for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
+               {
+                       //printf("(A-%d)", rta->rta_type);
+                       switch(rta->rta_type) {
+
+                       case CGW_FILTER:
+                       case CGW_MOD_AND:
+                       case CGW_MOD_OR:
+                       case CGW_MOD_XOR:
+                       case CGW_MOD_SET:
+                       case CGW_CS_XOR:
+                       case CGW_CS_CRC8:
+                               break;
+
+                       case CGW_SRC_IF:
+                               src_ifindex = *(__u32 *)RTA_DATA(rta);
+                               break;
+
+                       case CGW_DST_IF:
+                               dst_ifindex = *(__u32 *)RTA_DATA(rta);
+                               break;
+
+                       case CGW_HANDLED:
+                               handled = *(__u32 *)RTA_DATA(rta);
+                               break;
+
+                       case CGW_DROPPED:
+                               dropped = *(__u32 *)RTA_DATA(rta);
+                               break;
+
+                       default:
+                               printf("Unknown attribute %d!", rta->rta_type);
+                               return -EINVAL;
+                               break;
+                       }
+               }
+
+
+               printf("-s %s ", if_indextoname(src_ifindex, ifname));
+               printf("-d %s ", if_indextoname(dst_ifindex, ifname));
+
+               if (rtc->flags & CGW_FLAGS_CAN_ECHO)
+                       printf("-e ");
+
+               if (rtc->flags & CGW_FLAGS_CAN_SRC_TSTAMP)
+                       printf("-t ");
+
+               /* second parse for mod attributes */
+               rta = (struct rtattr *) RTCAN_RTA(rtc);
+               rtlen = RTCAN_PAYLOAD(nlh);
+               for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
+               {
+                       //printf("(B-%d)", rta->rta_type);
+                       switch(rta->rta_type) {
+
+                       case CGW_FILTER:
+                               printfilter(RTA_DATA(rta));
+                               break;
+
+                       case CGW_MOD_AND:
+                               printmod("AND", RTA_DATA(rta));
+                               break;
+
+                       case CGW_MOD_OR:
+                               printmod("OR", RTA_DATA(rta));
+                               break;
+
+                       case CGW_MOD_XOR:
+                               printmod("XOR", RTA_DATA(rta));
+                               break;
+
+                       case CGW_MOD_SET:
+                               printmod("SET", RTA_DATA(rta));
+                               break;
+
+                       case CGW_CS_XOR:
+                               print_cs_xor((struct cgw_csum_xor *)RTA_DATA(rta));
+                               break;
+
+                       case CGW_CS_CRC8:
+                               print_cs_crc8((struct cgw_csum_crc8 *)RTA_DATA(rta));
+                               break;
+
+                       case CGW_SRC_IF:
+                       case CGW_DST_IF:
+                       case CGW_HANDLED:
+                       case CGW_DROPPED:
+                               break;
+
+                       default:
+                               printf("Unknown attribute %d!", rta->rta_type);
+                               return -EINVAL;
+                               break;
+                       }
+               }
+
+               printf("# %d handled %d dropped\n", handled, dropped); /* end of entry */
+
+               /* jump to next NLMSG in the given buffer */
+               nlh = NLMSG_NEXT(nlh, len);
+       }
+}
+
 int main(int argc, char **argv)
 {
        int s;
@@ -241,34 +431,38 @@ int main(int argc, char **argv)
 
        int cmd = UNSPEC;
        int have_filter = 0;
+       int have_cs_xor = 0;
+       int have_cs_crc8 = 0;
 
        struct {
                struct nlmsghdr nh;
                struct rtcanmsg rtcan;
-               char buf[200];
+               char buf[600];
 
        } req;
 
-       char rxbuf[8192]; /* netlink receive buffer */
-       char ifname[IF_NAMESIZE]; /* internface name for if_indextoname() */
+       unsigned char rxbuf[8192]; /* netlink receive buffer */
        struct nlmsghdr *nlh;
        struct nlmsgerr *rte;
-       struct rtcanmsg *rtc;
-       struct rtattr *rta;
-       __u32 handled, dropped;
-       int rtlen;
+       unsigned int src_ifindex = 0;
+       unsigned int dst_ifindex = 0;
+       __u16 flags = 0;
        int len;
 
        struct can_filter filter;
        struct sockaddr_nl nladdr;
 
+       struct cgw_csum_xor cs_xor;
+       struct cgw_csum_crc8 cs_crc8;
+       char crc8tab[513] = {0};
+
        struct modattr modmsg[CGW_MOD_FUNCS];
        int modidx = 0;
        int i;
 
        memset(&req, 0, sizeof(req));
 
-       while ((opt = getopt(argc, argv, "ADFLs:d:tef:m:?")) != -1) {
+       while ((opt = getopt(argc, argv, "ADFLs:d:tef:c:x:m:?")) != -1) {
                switch (opt) {
 
                case 'A':
@@ -292,19 +486,19 @@ int main(int argc, char **argv)
                        break;
 
                case 's':
-                       req.rtcan.src_ifindex = if_nametoindex(optarg);
+                       src_ifindex = if_nametoindex(optarg);
                        break;
 
                case 'd':
-                       req.rtcan.dst_ifindex = if_nametoindex(optarg);
+                       dst_ifindex = if_nametoindex(optarg);
                        break;
 
                case 't':
-                       req.rtcan.can_txflags |= CAN_GW_TXFLAGS_SRC_TSTAMP;
+                       flags |= CGW_FLAGS_CAN_SRC_TSTAMP;
                        break;
 
                case 'e':
-                       req.rtcan.can_txflags |= CAN_GW_TXFLAGS_ECHO;
+                       flags |= CGW_FLAGS_CAN_ECHO;
                        break;
 
                case 'f':
@@ -318,6 +512,30 @@ int main(int argc, char **argv)
                        }
                        break;
 
+               case 'x':
+                       if (sscanf(optarg, "%hhd:%hhd:%hhd:%hhx",
+                                  &cs_xor.from_idx, &cs_xor.to_idx,
+                                  &cs_xor.result_idx, &cs_xor.prefix_value) == 4) {
+                               have_cs_xor = 1;
+                       } else {
+                               printf("Bad XOR checksum definition '%s'.\n", optarg);
+                               exit(1);
+                       }
+                       break;
+
+               case 'c':
+                       if ((sscanf(optarg, "%hhd:%hhd:%hhd:%512s",
+                                   &cs_crc8.from_idx, &cs_crc8.to_idx,
+                                   &cs_crc8.result_idx, crc8tab) == 4) &&
+                           (strlen(crc8tab) == 512) &&
+                           (b64hex(crc8tab, (unsigned char *)&cs_crc8.crctab, 256) == 0)) {
+                               have_cs_crc8 = 1;
+                       } else {
+                               printf("Bad CRC8 checksum definition '%s'.\n", optarg);
+                               exit(1);
+                       }
+                       break;
+
                case 'm':
                        /* may be triggered by each of the CGW_MOD_FUNCS functions */
                        if ((modidx < CGW_MOD_FUNCS) && (err = parse_mod(optarg, &modmsg[modidx++]))) {
@@ -345,7 +563,7 @@ int main(int argc, char **argv)
        }
 
        if ((cmd == ADD || cmd == DEL) &&
-           ((!req.rtcan.src_ifindex) || (!req.rtcan.dst_ifindex))) {
+           ((!src_ifindex) || (!dst_ifindex))) {
                print_usage(basename(argv[0]));
                exit(1);
        }
@@ -368,8 +586,8 @@ int main(int argc, char **argv)
                req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
                req.nh.nlmsg_type  = RTM_DELROUTE;
                /* if_index set to 0 => remove all entries */
-               req.rtcan.src_ifindex  = 0;
-               req.rtcan.dst_ifindex  = 0;
+               src_ifindex  = 0;
+               dst_ifindex  = 0;
                break;
 
        case LIST:
@@ -387,12 +605,23 @@ int main(int argc, char **argv)
        req.nh.nlmsg_seq   = 0;
 
        req.rtcan.can_family  = AF_CAN;
+       req.rtcan.gwtype = CGW_TYPE_CAN_CAN;
+       req.rtcan.flags = flags;
+
+       addattr_l(&req.nh, sizeof(req), CGW_SRC_IF, &src_ifindex, sizeof(src_ifindex));
+       addattr_l(&req.nh, sizeof(req), CGW_DST_IF, &dst_ifindex, sizeof(dst_ifindex));
 
        /* add new attributes here */
 
        if (have_filter)
                addattr_l(&req.nh, sizeof(req), CGW_FILTER, &filter, sizeof(filter));
 
+       if (have_cs_xor)
+               addattr_l(&req.nh, sizeof(req), CGW_CS_XOR, &cs_xor, sizeof(cs_xor));
+
+       if (have_cs_crc8)
+               addattr_l(&req.nh, sizeof(req), CGW_CS_CRC8, &cs_crc8, sizeof(cs_crc8));
+
        /*
         * a better example code
         * modmsg.modtype = CGW_MOD_ID;
@@ -451,78 +680,17 @@ int main(int argc, char **argv)
                                perror("netlink recv");
                                return len;
                        }
-                       nlh = (struct nlmsghdr *)rxbuf;
-                       if (nlh->nlmsg_type == NLMSG_DONE) 
-                               break;
-
-                       rtc = (struct rtcanmsg *)NLMSG_DATA(nlh);
-                       if (rtc->can_family != AF_CAN) {
-                               printf("received msg from unknown family %d\n", rtc->can_family);
-                               return -EINVAL;
-                       }
+#if 0
+                       printf("received msg len %d\n", len);
 
-                       /*
-                        * print list in a representation that
-                        * can be used directly for start scripts
-                        */
+                       for (i = 0; i < len; i++)
+                               printf("%02X ", rxbuf[i]);
 
-                       printf("%s -A ", basename(argv[0]));
-                       printf("-s %s ", if_indextoname(rtc->src_ifindex, ifname));
-                       printf("-d %s ", if_indextoname(rtc->dst_ifindex, ifname));
-
-                       if (rtc->can_txflags & CAN_GW_TXFLAGS_ECHO)
-                               printf("-e ");
-
-                       if (rtc->can_txflags & CAN_GW_TXFLAGS_SRC_TSTAMP)
-                               printf("-t ");
-
-                       /* check for attributes */
-
-                       handled = 0;
-                       dropped = 0;
-
-                       rta = (struct rtattr *) RTM_RTA(rtc);
-                       rtlen = RTM_PAYLOAD(nlh);
-                       for(;RTA_OK(rta, rtlen);rta=RTA_NEXT(rta,rtlen))
-                       {
-                               switch(rta->rta_type) {
-
-                               case CGW_FILTER:
-                                       printfilter(RTA_DATA(rta));
-                                       break;
-
-                               case CGW_MOD_AND:
-                                       printmod("AND", RTA_DATA(rta));
-                                       break;
-
-                               case CGW_MOD_OR:
-                                       printmod("OR", RTA_DATA(rta));
-                                       break;
-
-                               case CGW_MOD_XOR:
-                                       printmod("XOR", RTA_DATA(rta));
-                                       break;
-
-                               case CGW_MOD_SET:
-                                       printmod("SET", RTA_DATA(rta));
-                                       break;
-
-                               case CGW_HANDLED:
-                                       handled = *(__u32 *)RTA_DATA(rta);
-                                       break;
-
-                               case CGW_DROPPED:
-                                       dropped = *(__u32 *)RTA_DATA(rta);
-                                       break;
-
-                               default:
-                                       printf("Unknown attribute %d!", rta->rta_type);
-                                       return -EINVAL;
-                                       break;
-                               }
-                       }
-
-                       printf("# %d handled %d dropped\n", handled, dropped); /* end of entry */
+                       printf("\n");
+#endif
+                       /* leave on errors or NLMSG_DONE */
+                       if (parse_rtlist(argv[0], rxbuf, len))
+                               break;
                }
        }